职称英语考试理工类B级考试真题.doc

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1、2011年职称英语考试理工类B级考试真题　　LongerLivesforWildElephants(B级)　　Mostpeoplethinkofzoosassafeplacesforanimals,wherestragglessuchasdifficultyfindingfoodandavoidingpredatorsdon'texist.Withoutsuchproblems,animalsinzoosshouldlivetoaripeoldage1.　　Butthatmaynotbetruefor2thelargestlandanimal

2、sonEarth.Scientistshaveknownthatelephantsinzoosoftensufferfrompoorhealth.Theydevelopdiseases.jointproblemsandbehaviorchanges.Sometimes,theyevenbecomeinfertile,orunabletohavebabies.　　Tolearnmoreabouthowcaptivityaffectselephants,ateamofinternationalscientistscomparedthelifesp

3、ansoffemaleelephantsborninzooswithfemaleelephantslivingoutdoorsintheirnativelands.Zooskeepdetailedrecordsofalltheanimalsintheircare,documentingfactorssuchasbirthdates,illnesses,weightanddeath.Theserecordsmadeitpossiblefortheresearcherstoanalyze40yearsofdataon800AfricanandAs

4、ianelephantsinzoosacrossEurope.Thescientistscomparedthelifespansofthezoo-bornelephantswiththelifespansofthousandsoffemalewildelephantsinAfricaandAsianelephantsthatworkinloggingcamps3,overapproximatelythesametimeperiod.　　TheteamfoundthatfemaleAfricanelephantsborninzoosliveda

5、naverageof16.9years.Theirwildcounterpartswhodiedofnaturalcauseslivedanaverageof56years—morethanthreetimesaslong.FemaleAsianelephantsfollowedasimilarpattern.Inzoos,theylived18.9years,whilethoseintheloggingcampslived41.7years.　　Scientistsdon'tyetknowwhywildelephantsseemtofare

6、somuchbetterthantheirzoo-raisedcounterparts.GeorgiaMason,abiologistattheUniversityofGuelphinCanadawholedthestudy,thinksstressandobesitymaybetoblame4.Zooelephantsdon'tgetthesamekindofexercisetheywouldinthewild,andmostareveryfat.Elephantsociallivesarealsomuchdifferentinzoosth

7、aninthewild.wheretheyliveinlargeherdsandfamilygroups.　　AnotherfindingfromthestudyshowedthatAsianelephantsborninzoosweremorelikelytodieearlythanAsianelephantscapturedinthewildandbroughtto5/5zoos.Masonsuggestsstressinthemothersinzoosmightcausethemtohavebabiesthatarelesslikely

8、tosurvive.　　Thestudyraisessomequestionsaboutacquiringmoreelephantstokeepinzoos.Whi